Turbine inlet valve structure

ABSTRACT

Fluid flow control valves arranged in the valve chest of an elastic fluid turbine are formed with stems noncircular in cross section having slidable engagement with noncircular apertures formed in the valve lifting bar whereby the valves are prevented from spinning on their axes. The valve stems are formed with enlargements integrally united with the stems. The bar lifting rods are formed with enlargements integrally united therewith, the rod enlargements being spaced apart axially a distance equal to the vertical dimension of the lifting bar.

United States Patent [191 Nelson et a].

[451 Aug. 21, 1973 TURBINE INLET VALVE STRUCTURE Primary Examiner-RobertG. Nilson Attorney-J. Raymond Curtin et al.

[57] ABSTRACT Fluid flow control valves arranged in the valve chest ofan elastic fluid turbine are formed with stems noncircular in crosssection having slidable engagement with noncircular apertures formed inthe valve lifting bar June 5, 1972 Appl. No.: 259,701

137/63o'19 whereby the valves are Prevented from Pinning on 630 theiraxes. The valve stems are formed with enlargements integrally unitedwith the stems. The bar lifting rods are formed with enlargementsintegrally united therewith, the rod enlargements being spaced apartaxi- Field or's'i'iiIIIIIIIIIIIII' References Cited UNITED STATESPATENTS ally a distance equal to the vertical dimension of the liftingbar.

4 Claims, 7 Drawing Figures 2,385,537 Penthenny....................l37/630.19 3,625,241 Shields........................... 137/630 19lllill'iillllrli PATENTEDAUGZI I975 3,753.44 SHEET 1 OF 2 9 llllllPATENTED M1821 I975 SHEH 2 0F 2 III 0 FIG. 6

TURBINE INLET VALVE STRUCTURE BACKGROUND OF THE INVENTION In elasticfluid operated turbines employing a linear series of valves controllingthe admission of fluid to the turbine, valve failure occurs on occasion.The valve failure develops due to the magnitude of vibration set up inthe valve structure by the high velocity flow of fluid through the valvechest during operation of the turbine and also due to the spinning ofthe valves about their axes.

Formerly the upper ends of the valve stems were threaded for thereception of nuts to provide enlargements engaged by the valve liftingbar for movement of the valves from their respective seats. Theexcessive vibration resulted in failure of the valve stems in thethreaded area. That area of the problem is solved by the invention setforth in US. Pat. No. 3,625,241 to J. R. Shields, wherein theenlargements at the upper ends of the valve stems are integrally unitedwith the stems. However, the construction of that patent does not dealwith the problem of valve stem failure due to the spinning of the valvesin the lifting bar.

In one conventional arrangement, the valve lifting bar was notrestrained against vertical movement on the bar lifting rods, in thatarrangement the bar vibrated relative to the lifting bar. In anotherarrangement, the lower or inner ends of the lifting rods were threadedfor the reception of nuts for engagement with the lifting bar. In thatarrangement, the threaded portions of the lifting rods developedfailure.

SUMMARY OF THE INVENTION This invention is directed to an admissionvalve structure for fluid turbines wherein the lifting bar is oftwopiece construction. The pieces being clamped together in abuttingrelation, the abutting surfaces extending in a vertical plane. Thelifting bar structure is formed with a linear series of noncircularapertures, preferably of rectangular form, and the valve stems are ofcross sectional form comparable to the apertures in the lifting barstructure, whereby the valves are prevented from rotation. The liftingrods are formed with axially spaced apart enlargements which areintegrally united with the rods. The valve stems and the lifting rodsare inserted in the apertures of the lifting bar structure and the partsthereof are clamped together by fastening means, such as screws. I

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings,

FIG. I is a vertical sectional view of the valve chest with parts of thevalve actuating mechanism shown in elevation, the view is taken on aline corresponding to line 1-1, FIG. 2;

FIG. 2 is a view taken on line 22, FIG. 1;

FIG. 3 is a view in perspective of one part of the valve lifting barstructure;

FIG. 4 is a view in perspective of the other mating part of the valvelifting structure;

FIG. 5 is a view taken on line 5-5, FIG. 1;

FIG. 6 is a view in perspective of one of the valves; and

FIG. 7 is a view in perspective of the lower portion of one of thelifting rods.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, I0designates a portion of the turbine casing having a surface 11 formingthe bottom wall 0F the valve chest 12. The chest 12 is fixedly securedin fluid type relation to the casing 10 as by screws 13.

The bottom wall 11 of the valve chest is formed with a plurality offluid passages l4I7. A valve seat 20 is positioned in each of thepassages 14-17. The fluid passages and the valve seats are arranged in alinear series.

The top wall 23 of the valve chest is provided with guide bushings 25 inwhich sleeves 26 are mounted. Lifting rods 27 are slidably mounted inthe sleeves 26 which may be replaced when they become worn. The upperends of the rods 27 are threaded into rod ends 30, connected toactuating arms 31 pivotally mounted at 32 on supports 33, 34. The rodends 30 are pivotally connected to the arms 31 by links 35.

The inner ends of the lifting rods 27 are connected to a lifting barstructure 40. The bar structure 40 consists of two mating parts 41, 43,FIGS. 3 and 4. These parts are of elongated configuration and areclamped together by screws 44 extending through apertures 45 formed inthe bar part 43 and threaded into apertures 46 formed in the part 4!.

The bar structure 40 is formed with vertically disposed apertures, eachaperture being arranged in axial registration with a valve seat 20. Inthe arrangement shown in FIGS. 3 and 4, the lifting bar part 41 isformed with recesses 50, rectangular in cross section.

A valve 53 is provided for each of the valve seats 20. Each valve isformed with an integral stem 54 having a cross sectional form comparableto the cross sectional form of the apertures 50. As shown in FIG. 6, thestem 54 is rectangular in cross section and dimension for a sliding fitin the apertures 50 of like cross sectional form.

The upper ends of the valve stems 54 are provided with enlargements 57which are integrally united with the stems. The valve structures may beformed integrally by drop forging, o'r machined from a workpiece, or theenlargements 57 may be joined to the stems as by welding. The spacing ofthe enlargements 57 from the valves 53 varies from one valve structureto another as is conventional practice, see FIG. 1, whereby the valvesare lifted sequentially from the seats 20 upon upward movement of bar40.

The lower or inner portions of the lifting rods 27 are formed withenlargements 60, 61, FIG. 7. These enlargements are also integrallyunited with the lifting rods and are spaced apart axially a distancecomparable to the vertical dimension of the lifting bar.

As shown in FIGS. 5 and 7, the portion 63 of the lifting rodsintermediate the enlargements 60, 61 are of circular cross section.Preferably the diameter of the rod portions 63 are a close fit in therecesses 50, and the enlargements 60, 61 are spaced apart axially suchthat they are situated in close proximity to the upper and lower sidesof the bar structure 40.

With the bar structure illustrated, the portion 63 of the lifting barsare placed in a pair of the recesses 50 as illustrated in FIG. I. Thevalve stems 54 are placed in the remaining recesses 50. The mating part43 of the valve structure is then positioned on the part 41, overlyingthe open sides of the recesses 50, the part 43 is fixedly secured to thepart 41 by the screws 44. The part 41 may be formed with ribbed portions67, cooperable with a slot formed in the abutting surface of the part43, and having upper and lower side walls 68, 69. With that arrangementvertical forces are not transmitted directly to the fastening screws 44,and the parts 41, 43 are maintained in proper alignment.

The arms 31 are joined, rearwardly of the pivot 32, by a verticallydisposed web 71, the web 71 extends laterally from the support 33 and isintegrally connected to upper and lower rearwardly extending webs 72,73. The portions of the web 71, 72, 73 extending laterally from thesupport 33 are provided or formed with a bifurcated boss 75. A rod end76 is pivotally connected to the boss 75 and is adjustably connected tothe upper end of the actuating rod 77. Vertical reciprocation isimparted to the rod 77 by a servomotor device 80 attached to the turbinecasing. With this arrangement, vertical reciprocation is transmitted tothe lifting rods 27 to move the lifting bar structure 40 vertically formovement of the valves 53 into and out of engagement with the seats 20.

By the structure embodied in our invention, vibration in the lifting barstructure, the valves and the lifting rods is reduced to a negligibleamount and fracture of the parts is eliminated.

While we have described a preferred embodiment of our invention, it isto be understood that the invention is not limited thereto, but may beotherwise embodied within the scope of the following claims.

We claim:

1. A fluid admission valve structure for elastic fluid turbinescomprising a valve chest having a top wall and bottom wall, said bottomwall being formed with a linear series of vertically disposed passages,a valve seat in each of said passages, a valve lifting bar meansextending above said series of passages, said lifting bar means beingformed of two parts, fastener means detachably securing said partstogether, said lifting bar means being formed with a noncircularaperture axially aligned with each of said passages, a valve cooperablewith each of said seats, each of said valves having an integral sternslidably mounted in an apeture in said lifting bar means, said stemshaving a noncircular cross sectional form comparable to the noncircularform of said apertures, each of said stems being formed with an enlargedhead portion integrally united thereto, said head portions beingengageable by said lifting bar means upon upward movement thereof, apair of bar lifting rods fixed to said lifting bar means and beingslidably mounted in the top wall of said valve chest, said rodsextending outwardly from said top wall and being connected to meansoperable to impart vertical reciprocation thereto for vertical movementof said lifting bar means and like movement of said valves into and outof engagement with said seats.

2. A valve structure as set forth in claim 1 wherein the stems of saidvalves are insertable in and removable from said apertures uponseparation of the parts of said valve lifting bar means. I

3. A valve structure as set forth in claim 1 wherein said apertures insaid valve lifting bar means are rectangular in cross sectional form.

4. A valve structure as set forth in claim 1 wherein said valve liftingrods are fonned with enlargements integrally united thereto and spacedapart axially a distance comparable to the vertical dimension of saidlifting bar means.

1. A fluid admission valve structure for elastic fluid turbinescomprising a valve chest having a top wall and bottom wall, said bottomwall being formed with a linear series of vertically disposed passages,a valve seat in each of said passages, a valve lifting bar meansextending above said series of passages, said lifting bar means beingformed of two parts, fastener means detachably securing said partstogether, said lifting bar means being formed with a noncircularaperture axially aligned with each of said passages, a valve cooperablewith each of said seats, each of said valves having an integral stemslidably mounted in an apeture in said lifting bar means, said stemshaving a noncircular cross sectional form comparable to the noncircularform of said apertures, each of said stems being formed with an enlargedhead portion integrally united thereto, said head portions beingengageable by said lifting bar means upon upward movement thereof, apair of bar lifting rods fixed to said lifting bar means and beingslidably mounted in the top wall of said valve chest, said rodsextending outwardly from said top wall and being connected to meansoperable to impart vertical reciprocation thereto for vertical movementof said lifting bar means and like movement of said valves into and outof engagement with said seats.
 2. A valve structure as set forth inclaim 1 wherein the stems of said valves are insertable in and removablefrom said apertures upon separation of the parts of said valve liftingbar means.
 3. A valve structure as set forth in claim 1 wherein saidapertures in said valve lifting bar means are rectangular in crosssectional form.
 4. A valve structure as set forth in claim 1 whereinsaid valve lifting rods are formed with enlargements integrally unitedthereto and spaced apart axially a distance comparable to the verticaldimension of said lifting bar means.